In a direct SSC using a correlator such as a surface acoustic wave (hereinbelow abbreviated to SAW) convolver, as dividing means for a communication channel in the case where an m sequence serves as spreading codes, it is conceivable to utilize not only the sort of the m sequence but also the initial phase of the m sequence both on the sender and the receiver sides. The algorithm for determining the data demodulation timing and the information concerning the initial phase and so forth have been already disclosed by the same applicant of this invention in JP-A-59-2733.
However the result obtained by the algorithm for determining the information concerning the initial phase of the m sequence (hereinbelow called simply initial phase information) can be applied only to the case where a simple construction type m sequence generator is used and no algorithm for determining the initial phase information, which can be applied in a general manner both to the simple construction type and the modular type m sequence generators, were known.